BEGIN {
	if ( ARGC != 3 ) {
		printf( "Usage:gawk -f div.awk num=[number] filename\n" );
		exit;
	}
}
{
	key = NR % num;
	outfile = sprintf( "%s.%d", ARGV[2], key + 1 );
	printf( "%s\n", $0 ) > outfile;
}